Furnace grate



oct. 7, 1941. M A', HOFF-r .E1-AL 2,257,956

` FURNACE GRATE Filed March 17, 1939 2 Sheets-Sheet 2 HHH ATTORNEYSPatented ct. 7, 1941 UNITED STATES PATENT oisleli:

i FURNACE GRATE Maurice A. Hoffi and Nick T. Puckett, Indianapolis, Ind.

Application Maren 17, 1939, serial No. 262,391

4 Claims.

The present invention relates to improvements infurnaces andparticularly to the grates of furnaces of that type adapted for burningsuch fuels as refuse, waste, rubbish, garbage, and like material. Theinvention is particularly adapted for burning material having a highmoisture content. l

One of the objects of the invention is to provide a grate which willinclude water-cooled tubular grate bar supporting members and suitablegrate bars supported thereby .in such a manner that the grate bars maybe moved for the purpose of breaking up the fuel bed, when desired.V

Another object of the invention is to provide water-cooled supportingmembers carrying grate bars which may be readily replaced in event ofdamage and which will be substantially held against displacement.

For the purpose of disclosing the invention, an embodiment thereof isillustrated in the accompanying drawings, in which:

Fig. 1 is a longitudinal sectional. view of a furnace having embodiedtherein the improved form of grate;

Fig. 2 is a partial plan view of a grate bar embodying the invention;

Fig. 3 is a partial side elevation thereof, certain parts being brokenaway for fuller illustration;

Fig. 4 is a detailed sectional view on the line 4-4 of Fig. 3.

Fig. 5 is an enlarged plan of a portion of the grate showing moreparticularly the trunnion support; and

Fig. 6 is an enlarged detail plan showing more fully a second form oftrunnion support.

In the embodiment of the invention illustrated, a plurality ofwater-cooled tubes I is provided, which tubes are arranged side by sideand extend from front to back of the furnace. These tubes,

at their lower ends are connected together byl a header 2 which may besupported from a suitable bracket 3 extending forwardly from the bridgewall of the furnace. The tubes, at their upper ends, are connected to asimilar header 4 resting upon a supporting wall 5 in the furnace andthese tubes are preferably inclined at an angle from their top end totheir bottom end of approximately 42.

The tubes extend, as before stated, longitudinally from the front to therear of the furnace and are suitably spaced apart to provide betweenthem, grate-receiving spaces 6. At the upper end between the pair ofgrate-receiving spaces,

is arranged transversely extending supporting bars 'I which arepreferably welded to the walls of the tubes. These transverselyextending supporting webs have formed in their upper surfaces trunnionsockets 8. At spaced intervals throughout the length of the upperportion of the tubes, additional trunnion sockets are provided, and aseach of these is the same, the description of only one is necessary. Acooperating trunnion socket, for the trunnion socket of the' charactershown at 8 comprises a transverse web 9 welded to the Walls of the tubesvanddisposed between the tubes, and these webs have center openings I8therein. A componentweb Il, similar to web l, is associated with the web9 and this has an open topped trunnion socket I2. yThis web is. likewisewelded to the walls of the tube, being disposed between a pair of tubesVand the webs 9 and Il are connected together by a longitudi-v nallyextending center web I3. As a matter of fact, a complete structure inthe form of a casting is formed by the webs 9 and I I and theirconnecting web I3, the whole structure being welded between ytheadjacent tubes I. There may be as many of-these grate supporting webs asdesirable, depending upon the length of the grate to be used in thefurnace.

A third type of trunnion casting is provided which is adapted to belocated further down the length of the tubes. This casting comprises aplurality of transversely extending webs I4, l5 and I6, connected by acenter web I1 and provided on its upper edge with a trunnion socket I8.The above trunnion castings are for the purpose of receiving andsupporting grate bars. The particular type of grate bar illustrated asbeing supported by these webs comprises a bar I9 having grate openings20 in the top surface thereof and provided with downwardly extendingside flanges 2| to which are attached rocking lugs 22. The ends of thesegrate bars are provided with pivot pins 23 and 24 and when the bars areassembled in position, one of the pivot pins, 23, is preferably socketedin a trunnion opening I8, while the top pin is dropped down into atrunnion socket I2. By this arrangement, the grate bar may readily beassembled in position. After the pin 24 has been dropped into a trunnionsocket I2, and it will be noted that where the pinions more or lessabut, there is a space between the webs 9 and II. This space ispreferably closed by a cross bar 25 having reduced projections 26 whichbar drops between the water cooling tubes and is provided with a lip 21overlapping the trunnion socket I 2,

At the lower end of the grate, there are preferably arranged pusher barsof the type illustrated and to accomodate these pusher bars, a type ofcasting is welded to the adjacent faces of the water tubes. One type ofcasting comprises the cross bars 28 and the inwardly projecting lugs 29which have on their upper faces trunnion sockets 30. The structurecomprising the lugs 29 and the cross bars 28 preferably comprise onecasting which is welded to the opposite faces of the pairs of watertubes and comprises a support for a pusher grate 3| having the uppergrate bar portion thereof provided with spaced apart ngers 3|. The loweror front end of this pusher bar has a restricted neck 32 provided withtransversely extending pins 33 adapted to socket in the trunnion sockets3i). These hollow pusher fingers extend downwardly, being provided withdownwardly projecting arms 34 having bifurcated fingers 35 adapted toreceive rocker rods 36. There may be as many of these pusher fingerssupporting castings as desired, dependent, of course, upon the length ofthe grate.

At the lower end and adjacent the headers 2, there are providedinternally extending lugs 3i having on their top surfaces trunnionsockets 33 to receive the trunnion pins 33 of the bottommost pusherfingers. The .only difference between these supporting castings and theones above is that the transverse ller cross bars 28 are dispensed with.It is .to be observed that the transverse cross bars provide fillergrates for the space between the top edge of one pusher` finger and thetrunnion edge ofthe next adjacent pusher finger.

It is obvious that the grate bars 2B may be rocked by suitable rockingmechanism manipulating the projections 22 and that the pusher bars 3|are rocked longitudinally of the grate for the purpose of feeding thefuel forward toward the lower end.

It is obvious that the tubes l may be set at any desired angle and mayhave different portions thereof set at any desired angle throughouttheir length. To accomplish this, these tubes may be bent either in acontinuous curve or by short curves at different points to obtaindifferent angular inclinations of the tubes.

We claim as our invention:

1. A furnace grate comprising in combination,

a plurality of' water tubes arranged in spaced side by side relation,grate bar sections disposed between adjacent pairs of tubes, a portionof said sections having trunnion pins at their opposite ends, andtransversely extending supports for said sections welded to the opposedfaces of tube pairs and extending between the tubes, said supportshaving trunnion recesses therein for the reception of the trunnion pinsof the grate bar sections.

2. A furnace grate comprising in combination, a plurality of water tubesarranged in spaced side by side relation, grate bar sections disposedbetween adjacent pairs of tubes, a portion of said sections havingtrunnion pins at their opposite ends and transversely extending supportsfor said sections welded to the opposite faces of the tubes andextending between the tubes, certain of said supports having trunnionpin recesses in the side faces thereof and other of said supports havingtrunnion recesses in the top faces thereof for the reception of thetrunnion pins on said grate bar sections.

3. A furnace grate comprising in combination, a plurality of water tubesarranged side by side in spaced relation, pairs of grate bar supportseach having a trunnion socket therein and welded to adjacent watertubes, and grate bars having oppositely disposed trunnions resting inthe trunnion sockets of the grate bar supports and between the watertubes.

4. A furnace for burning refuse fuels and having a front wall and abridge wall, including a grate comprising a hearth, downwardly inclinedand extending from the intake end of the furnace toward the rear, aplurality of water tubes disposed side by side in spaced relation andextending from front to rear of the furnace and having their upper endssupported above the surface of said hearth and their lower endssupported adjacent tlie bridge wall and grate bars mounted between saidtubes beyond the hearth, said grate bars having openings thereinpermitting the inlet of air beneath the fuel bed, the top surface ofsaid grate bars being below the top surface of the tubes and the fuelbeing slidably supported on the top surface of the tubes and leaving aspace between the bottom surface of the fuel and the top surface of thegrate bars.

MAURICE A. HOFFT. NICK T. PUCKETT.

